Fast National ratings for Tuesday, July 30, 2013The CW's competition series "Capture" got off to a mediocre start Tuesday following "Whose Line Is It Anyway?," which remained solid and grew a little with its second half-hour. "Capture's" premiere ratings were up a little from the debut of "Perfect Score" a couple weeks ago."America's Got Talent" once again led the night by a wide margin, although it was down a little bit from last week. "So You Think You Can Dance" was about even with last week.NBC averaged 7.6 million viewers and a 4.6 rating/8 share in households for the night, beating out CBS (6.2 million, 4.2/7) for the top spot. FOX came in third with 4.1 million viewers and a 2.6/4. ABC (3.3 million, 2.4/4) took fourth, and The CW (1.7 million, 1.0/2) brought up the rear.NBC also led the 18-49 demographic with a 2.1 rating. FOX finished second in the demo with a 1.4,...